Serological report of pandemic (H1N1) 2009 infection among cats in Northeastern China in 2012-02 and 2013-03

Table 3 Prevalence of elevated antibody titers against a canine influenza H3N2, a seasonal influenza H1N1, and A(H1N1)pdm09 among cats by hemagglutination inhibition (HI) assay, northeastern China ^a

HI assay virus	Number	Antibody titer					Number of specimens with titers ≥1:40 (%)
HI assay virus	Number	<1:20	1:20	1:40	1:80	≥1:160	Number of specimens with titers ≥1:40 (%)	OR(95% CI)^b
H3N2	1140	704	325	51	24	36	111 (9.7)	Reference
H1N1	1140	911	205	16	5	3	24(2.1)	5.02[3.20-7.86]
Pdm09	1140	518	382	123	52	65	240(21.5)	0.40[0.32-0.52]

^aH1N1 = A/Brisbane/59/2007(H1N1); H3N2 = A/canine/Guangdong/2/2011(H3N2); Pdm09 = A/California/7/2009(H1N1pdm09).
^bThe statistical tests about the association between difference virus strains; OR, odds ratio; CI, confidence intervals.

ISSN: 1743-422X